WOPI - System administrator has blocked add-ins from the Office store

Question

Hello!

I have a question about add-ins with WOPI. When I want to add Office Add-In from the Microsoft Store (AppSource) to a Word document opened with our WOPI integration in the browser, the error, that the system administrator has blocked add-ins from the Office store is displayed.
The message is also displayed on any other add-in from the Office store, so the issue is probably not about our add-in itself.

Previously, the error message was that the add-in was blocked to secure the data, so we have implemented the „App_IsFrameTrusted“ which then changed the error message to the one above.

What configuration are we missing here to enable add-ins from the store?
We implement the GetFileInfo endpoint, but I could not find any office store related property there.

Adding „host_install_addins“ to the form submit POST request for the office IFrame also does not work (It just does nothing), probably due to the error above.

I had a Microsoft support conversation some years ago about a topic in this area, there was a „HostAllowedOfficeStore“ property mentioned, but I could not find any documentation about that, and it seems that this is not part oft he GetFileInfo request, we did not follow up the issue back then.

There is also no useful information in the browser console or request log.

Any help about this?

Thank you and regards,
Dominik

Answer 1

To enable add-ins from the Office Store when using WOPI, you need to ensure that the appropriate configurations are in place. Here are some steps and considerations:

1. Check WOPI Host Configuration: Ensure that your WOPI host is configured to allow add-ins. This includes verifying that the HostAllowedOfficeStore property is set correctly. While documentation on this property is limited, it is crucial for enabling Office Store add-ins.
2. App_IsFrameTrusted: Since you mentioned implementing App_IsFrameTrusted, ensure that it is correctly set up and that your add-in is trusted to run in an iframe. This is necessary for the add-in to function properly within the WOPI context.
3. GetFileInfo Endpoint: While you have implemented the GetFileInfo endpoint, ensure that it includes all necessary properties that might affect add-in permissions. If there are any additional properties related to add-in permissions, they should be included in the response.
4. Security Settings: Verify that the security settings in your environment do not block add-ins from being installed. This may involve checking firewall settings or other security configurations that could prevent access to the Office Store.
5. Trusted Sites: Make sure that the domains associated with your add-ins are added to the list of trusted sites in your browser settings, as this can affect the ability to load add-ins from the Office Store.

If you continue to face issues, consider reaching out to Microsoft support for more specific guidance related to your WOPI integration and add-in configurations.

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References:

• Enable Microsoft 365 Add-ins provided by a WOPI host
• Troubleshoot user errors with Office Add-ins